Different kettle of fish regarding type and purpose, but very sad coming days after Colin Barnett's breathless launch of seaplane tours to splash down in Swan River.

http://https://au.news.yahoo.com/wa/...tourism/#page1

Headmaster
"So, the velocity change is still 200 kts"

I totally agree , but if say rate 2 turn ie 30 seconds the time available to accelerate this heavy mass is too short.
That is my experience, many times, especially in jetstream holding patterns.

Amazing that so many people STILL get confused by airspeed and groundspeed...read the article and stop spouting rubbish that others believe and repeat.

The bottom line is FORGET about groundspeed, the wing does not care about it.

However pilot perception CAN be influenced by changing groundspeed leading to PILOT INDUCED issues.

Having made around 5000 turns onto base in aircraft from 2t to 70t, up to 30 AoB, in conditions that have given me a sudden tailwind, I call BS on all the speed and wind theories. I'm sticking with stalling AoA (possibly combined with low IAS) being exceeded and more than happy to eat humble pie if this turns out to be wrong.

So, a rate 2 turn gives a constant rate of change of heading. As stated in my examples above, it is still a velocity change of 200 knots over 30 seconds for both cases. Inertia is the same. Rate of change of direction relative to the air mass is exactly the same.

As for holding, I am not aware of what system you use in that aircraft. All aircraft I have flown for the last 20 years have FMS and fly a ground track - not constant angle of bank. This is why there are speed variations - variations in rate of turn to make good the ground track.

From what I have seen from the various video clips of the crash, it would appear to be very similar to the B52 crash at Fairchild AFB in Washington where the crash was attributed to cross controls and a lower wing stall. I have also seen a video of another crash in the US, this time of a Cessna at an air show which did exactly the same thing.

Really? The in the jets I have flown the FMS flys over the holding fixed then rate one outbound, the "width" of the hold being determined by wind effect. Then the outbound leg is determined either by time or leg length in the FMS, the inbound turn varies with wind but not over rate one so can lead to an overshoot and re intercept of the inbound. Admittedly the better ones do vary heading outbound to allow for wind effect to intercept inbound cleanly, therefore not tracking parallel.

None of this made one bit of difference to the viability of airflow over the wing, even with 100 knot crosswind.

Just heard on ABC news (can't be arsed linking quote, trust me I'm as reliable as Facebook) that the investigation will/may take up to a year to determine the cause. Really? That long?

Text messages show that pilot was concerned about temperature and lack of wind

Swan River plane crash: Perth cancels Skyworks

Thread-drift but...
 

That doesn't make sense (and certainly doesn't happen on my jalopy). If you have a hundred knot headwind into the HP, the outbound cannot be Rate 1 as there would be no chance of turning inbound anywhere near the HP inbound track.

The outbound turn into a headwind can be way less than rate 1 (sometimes only 5°) because it needs to go wider to allow for the tailwind on the inbound turn.

For those who still believe in the old turning downwind furphy, despite the best efforts of the headmaster et al: Have a think about what happens if you fly constant-AOB orbits in a jet at higher levels in a steady 100 kt jetstream. Does the jet just go round and round at pretty much constant IAS, or does it alternate between stalling and overspeeding as it turns in and out of the wind?

As is sometimes the case, you are absolutely correct. I meant to say, MAX of rate one, often lower.

The point being NOT a ground track as suggested above.

(PS I know YOU get this A)

Looking at that pix just before impact. Thank you -- The Wawa Zone.
Rudder Neutral.
Elevators Neutral.
Flaps - Not Down
Aileron - Set for Left Turn ?

Ahead of the Pilot what happened apparently.

Ailerons full hard right.

One can only guess if the low level and surface winds had any impact on the aircraft involved, which factor could possibly have been a negative one in the conditions leading to the crash.
The nearest surface weather-measuring site to the crash site, is at Melville Water, at Inner Dolphin Pylon.
This weather-measuring point is about 2kms from the crash site, and would give a good indication of the surface winds on Perth Water. The crash occurred on the SE end of Perth Water.

Inner Dolphin Pylon

Melville Water is the next large stretch of open water in the Swan River, just downstream of the Narrows Bridge.
Perth Water is the open stretch of water opposite Perth city, where the Mallard was intending to land.

At the time of the crash (approx 17:00Hrs local time), the surface wind at Melville Water was from the SW at 12kts, gusting to 14 kts.
At the previous 16:30Hrs reading, the wind was WSW at 14kts, gusting to 17Kts - and at 17:30Hrs, the wind was from the SW at 11Kts, gusting to 13Kts.

Normally, in Summer, a strong SW sea breeze blows across Perth and its suburbs in the afternoons, usually appearing between 11:00Hrs and 14:00Hrs.
On Australia Day, because of a strong low pressure trough located over Perth city and suburbs, the sea breeze was very weak, resulting in only a very modest breeze.

The aircraft was initially heading approximately SE and banked around to the NE, which is when the stall/port wing drop, is first observable and highly noticeable.

This effectively means the aircraft would possibly have been flying SE with a very modest crosswind, but running into a very modest tailwind on the left turn.

It's entirely likely the left turn, which changed the airflow from crosswind to tailwind, along with reduced airspeed in the bank, led to the port wing stall, and the resultant unrecoverable situation.

Latest Capital City Observations Melville Water

A screenshot of the relevant Melville Water readings around the time of the crash. Unfortunately, a number of the measurements readings from this site, were inoperative at the time.

https://s28.postimg.org/s24v1wfd9/Melville_Water.jpg

737-Ng FCOM
Other types will no doubt be different. There are other protections not mentioned above as well, ie, it's not going to throw you into a 30 AOB at FL 410 ISA +15 !
Personally I think the argument is about inertia not momentum and we are actually talking about windshear.
Do the mathematical calculations still produce the same result if we hypothesise the turn taking only one second? I think they do, if you have faith in them we could jimmy up a 100knot negative windshear over one second and gather some data for the equations :)
( meant in a funny way, not an antagonising way )
Obviously 100kt negative windshear will see something happen, if you drag it out over a two minute hold entry then the results are benign.
Anyway, I may be wrong so I'd like to see the calculations done for one second rather than two minutes.
Cheers.

Anyone know what the effect of hitting the water would have had on the props? Would hitting the water have the same effect as and on land where prop blades tend to bend back significantly when hitting the ground under high power settings?
Images on the West Australian website today showing the recovery of the aircraft show no apparent damage to the props on one engine and only a slight bend to one prop blade on the other engine.


https://thewest.com.au/news/wa/plane...-ng-b88367962z


Is this an indication that the engines weren't producing power at the time of the accident?

One of the better videos I've seen of the Mallard crash - the initial video, taken by someone standing on the SE foreshore of Perth Water.

Isn't this an example of what everyone has been saying earlier in this thread is complete BS?

The aircraft doesn't care if it's blowing 300 knots, it just flies merrily along its' way.

What does matter is if a pilot tries to get to a certain spot to land and misjudges their base and final turn due to the ground track, and ends up turning too tight in order to make the intended landing point.

Are you a pilot? If so, you will need to sit your theory again.

The video reminded me a bit of this accident. Very different in size of aircraft but similar in outcome.

Yes, the physics probably will be shown to be similar.

However, probably not all that reasonable to compare the Perth mishap with Holland's cowboy attitudes. While the one, possibly, will prove to involve an unfortunate degree of inexperience ... the other pilot, while having considerable experience, led spades in wilful stupidity which proved to be trumps on the day.

Dr Kern's article is worth a read, I think.

While I'm not overly interested in buying into reruns of the downwind turn arguments, the presence/absence of horizontal/vertical shear is very relevant and is, I suspect, a major cause of much of the confusion. It is worth noting that the albatross exploits the latter consideration most competently.

Thanks, I know I'm very tired today, however I thought what I was reading contained zero elements of fact!

Low and slow turns with an upwind carry a risk of a visual perception that the pilot needs to increase bank to complete a "normal" turn over ground. This is because the visual pilot is seeing landmarks pass by close to the aircraft telling them that the turn isn't meeting expectations Not being a pilot that's ever considered landing on the wet stuff is this visual perception still relevant over water where I presume it would be different due to lack of moving landmarks.

But if that 300kts wind turns from a crosswind to a tailwind, within the space of a few seconds, you would expect some small alteration in the aircrafts flying position? Such as a loss of height?
In the initial video above, I see a Mallard travelling at a fairly steady altitude up until 17 seconds. At 18 seconds, it's losing altitude. At 19 seconds, the port wing is dropping dramatically. At 21 seconds, it's unrecoverable, due to a lack of altitude.

What is difficult to see in the video (due to the angle of videoing), is if the loss of altitude and port wing drop, is purely attributable to increased AOA, or loss of airspeed, due to initially flying too close to stall.

Errrrm....onetrack... when flying, an aircraft is always flying into a 'headwind' equal to TAS...

OneTrack, are you a qualified pilot, be it RA-Aus, GA or otherwise? I'm curious...

Because if you are... then this has not been explained to you in a way in which you have understood it and I would suggest that you speak to an instructor for further clarification.

The aircraft will fly the same through the air regardless of whether it is flying in zero wind, or 300 knots.

No, I'm not a pilot, or I would have that on my profile. I did take out basic pilot studies many years ago, but never completed them, due to other commitments.

So would not turning into a tailwind exhibit the same symptoms of windshear?

What does "turning into a tailwind" mean?

If the wind is a constant velocity an aircraft in the air never turns into a tailwind. The wind will affect the aircraft's groundspeed and track depending on which way the aircraft is heading, but the aircraft's TAS is not affected by the wind.

Now if it's a 300 kt northerly at 200' and a 300 kt southerly at 100', the aircraft will be destroyed on descent...

Thanks for your honesty.

It doesn't matter which way the aircraft is travelling in the 300knot wind, it simply flies normally as every *molecule* of air is moving at the same speed so the airframe is none the wiser.

What screws things up is when the pilot tries to get to a specific point on the ground or point of reference to be at by a certain altitude and with the 300 knots of wind, it will be extremely difficult to judge, therefore a pilot may pull a much steeper turn than normal to get to that point in time. Speed may also be reduced to allow the aircraft to make the point, which can result in a stall. The aircraft needs to be flown fully within its documented flight parameters, regardless of the wind speed.

Just remember that you're standing on a planet that's evolving
And revolving at 900 miles an hour.
It's orbiting at 19 miles a second, so it's reckoned,
The sun that is the source of all our power.
Now the sun, and you and me, and all the stars that we can see,
Are moving at a million miles a day,
In the outer spiral arm, at 40,000 miles an hour,
Of a galaxy we call the Milky Way.

.....and I don't feel any of it no matter which way I turn. :hmm:

Onetrack.

16 seconds into that video the ailerons are already going right.

Steve

Really? An upwind?

Squawk7700, thanks for your patience and explanation. I'm happy to have my lack of knowledge/understanding exposed and discussed, if it means only one pilot is saved from making a fatal error anytime in the future. We all learn by discussion and demonstration, and one should never stop learning.

What is of concern, of course, is that Peter Lynch was a supposedly fully qualified and experienced pilot - yet he managed to stoof his aircraft in, with what appears to be a very basic flying error.
I'm hazarding a guess that he didn't have low-level flying training and qualifications? - which, if true, leads to a lot more questions, as to why he was allowed to fly into the Skyworks display? :(

What is required to get approval for a display of this type? Or was he just showcasing the aircraft? It does seem a pretty small area for an aircraft of that size to be manoeuvring in, and no escape route in the event of something going wrong such as becoming assymetric.

Without wishing to comment in specifics of the accident :

FWIW the dangers/differences between upwind and downwind turns at low level were regarded as so significant that they used to be taught or at least demonstrated by (UK) Central Flying School instructors as part of the first low level flying lesson on a light piston aircraft , I'd guess/hope it's still taught elsewhere. As someone has already pointed out the major threat was regarded as trying to tighten a downwind turn or "wrap a turn up" to overfly a ground datum.

Oh gawd, here we go.

More approvals and training and qualifications and regulations? To land an amphibious aircraft on the water?

The ways in which pilots usually "stoof in" are well known. And those ways are usually "very basic" errors. Perhaps education, education and more education about the lessons that have been learned over and over would be a more effective solution.

This article makes interesting claims.

"...Mr Lynch had also been battling with the Civil Aviation Safety Authority to allow him to fly in the Australia Day air show right up until the 11th hour.The approval was finally granted on January 24 and a delighted Mr Lynch left a voice message on Mr McCormack’s phone that day saying: “Guess what mate, I got my type rating and everything through from CASA... and I am pretty happy about that as it means I will be in the show.”

No Cookies | Daily Telegraph

:bored:

One question; Is anyone who has posted on this thread an Ag Pilot? Or has anyone a low level endorsement?:confused:

I'm almost tempted to say not!